GMC SIERRA DENALI 2002 Manual page 103

The switch is located on the instrument panel.
2WS: In this mode the vehicle will operate like any
other vehicle with two wheel steering. If you want to
use 2WS and your vehicle is not in this mode, press the
4 Wheel Steer button until the 2WS indicator, located to
the right of the 4 Wheel Steer button, lights up. If the
2WS indicator is flashing you will have to center the
steering wheel by turning it to the left or right.
4WS: In this mode all four wheels will help steer the
vehicle. If you want to use 4WS, and your vehicle is not
in this mode, press the 4 Wheel Steer button, until the
4WS indicator, located to the right of the 4 Wheel Steer
button, lights up. If the 4WS indicator is flashing you
will have to center the steering wheel by turning it to the
left or right.
2-30
Slower Speed Mode (below 40 mph/64 kph)
At slower speeds the steering will operate in the lower
speed mode. This means the front and rear wheels will
turn in opposite directions. This helps the vehicle make
tighter turns, such as during parking, cornering and
turning into tight spaces.